Re: [PATCH] drm/modes: Replace deprecated simple_strtol with kstrtol

[Cong Liu]

Dear Jani,

I want to apologize for the incorrect patch I submitted. You are right 
that the recommended replacements are not suitable drop-in replacements 
and I clearly did not test the changes thoroughly.
The kstrtol function requires null-terminated strings, so it is not 
appropriate for the conversion needed here. Given the issues, it is best 
to maintain the original implementation for now.

Best Regard.
liucong

On 2024/2/1 18:03, Jani Nikula wrote:
> On Thu, 01 Feb 2024, Cong Liu <liucong2@xxxxxxxxxx> wrote:
> > This patch replaces the use of the deprecated simple_strtol [1] function
> > in the drm_modes.c file with the recommended kstrtol function. This change
> > improves error handling and boundary checks.
> >
> > [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull
> >
> > Signed-off-by: Cong Liu <liucong2@xxxxxxxxxx>
>
> This is completely wrong, and obviously not tested at all.
>
> The recommended replacements are *not* drop-in replacements. Look into
> the documentation of the functions.
>
> BR,
> Jani.
>
> > ---
> >   drivers/gpu/drm/drm_modes.c | 10 +++++-----
> >   1 file changed, 5 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
> > index 893f52ee4926..fce0fb1df9b2 100644
> > --- a/drivers/gpu/drm/drm_modes.c
> > +++ b/drivers/gpu/drm/drm_modes.c
> > @@ -1942,7 +1942,7 @@ static int drm_mode_parse_cmdline_bpp(const char *str, char **end_ptr,
> >   		return -EINVAL;
> >   
> >   	str++;
> > -	bpp = simple_strtol(str, end_ptr, 10);
> > +	bpp = kstrtol(str, end_ptr, 10);
> >   	if (*end_ptr == str)
> >   		return -EINVAL;
> >   
> > @@ -1961,7 +1961,7 @@ static int drm_mode_parse_cmdline_refresh(const char *str, char **end_ptr,
> >   		return -EINVAL;
> >   
> >   	str++;
> > -	refresh = simple_strtol(str, end_ptr, 10);
> > +	refresh = kstrtol(str, end_ptr, 10);
> >   	if (*end_ptr == str)
> >   		return -EINVAL;
> >   
> > @@ -2033,7 +2033,7 @@ static int drm_mode_parse_cmdline_res_mode(const char *str, unsigned int length,
> >   	int remaining, i;
> >   	char *end_ptr;
> >   
> > -	xres = simple_strtol(str, &end_ptr, 10);
> > +	xres = kstrtol(str, &end_ptr, 10);
> >   	if (end_ptr == str)
> >   		return -EINVAL;
> >   
> > @@ -2042,7 +2042,7 @@ static int drm_mode_parse_cmdline_res_mode(const char *str, unsigned int length,
> >   	end_ptr++;
> >   
> >   	str = end_ptr;
> > -	yres = simple_strtol(str, &end_ptr, 10);
> > +	yres = kstrtol(str, &end_ptr, 10);
> >   	if (end_ptr == str)
> >   		return -EINVAL;
> >   
> > @@ -2100,7 +2100,7 @@ static int drm_mode_parse_cmdline_int(const char *delim, unsigned int *int_ret)
> >   		return -EINVAL;
> >   
> >   	value = delim + 1;
> > -	*int_ret = simple_strtol(value, &endp, 10);
> > +	*int_ret = kstrtol(value, &endp, 10);
> >   
> >   	/* Make sure we have parsed something */
> >   	if (endp == value)